Sewing machine



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' SEWING MACHINE May zo, 1947..-

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SEWING MACHINE Filed May 21, 1945 s sheets-sheet 2;

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SEWING MACHINE Filed May 2l, 1945 3 Sheets-Sheet 5 C6@ INVENToR.

)/zgeddgz/ Patented May 20, 1947 SEWING MACHINE Clarence S. Best, Belvidere, Ill., .assigner to National Sewing Machine Company, Belvidere, Ill., a corporation of Illinois Application May 21, 1945, Serial No. 594,808

8 Claims.

This invention relates to limprovements .in sewing ,machines and particularly to a machine provided with drop feed mechanism and improved means for operating the feed dog to impart thereto the combined `rise-and-fall and feed-andreturn movements, in a positively defined path, for efficiently feeding the work.

Sewing machines heretofore have been provided with means for producing `ordinary sewing, that sewing in which the work is moved by the feed dog away from the operator, and for producing yreverse sewing, in `which the work is moved by the feed dog toward the operator. For certain kinds of work, particularly for darning and monding andthe like, itis desirable to manipulate the `work back and forth without having to actuate reversing mechanism for alternating the directhm 'of movement of the feed dog. To enable the operator to move the work back and forth freely, as required, without resorting to the use of reversing mechanism, it is necessary to drop the feed dog into inoperative position below the level of the bed plate of the machine. One of the objects of this invention is to produce improved drop feed mechanism for the purpose stated.

Another object of the invention is to provide novel and eflicient mechanism for driving the shafts which impart to the feed dog ythe ccmbined rise-and-fall and push-and-pull motions. As is well understood in the art, the feed dog has imparted to it .certain movements in the order stated: rise, push (work-engaging) fall, and pull (below the level of the work) and these cycles of motion may be clockwise or anticlockwise depending on whether the `machine is set for ordinary or reverse sewing.

Another `important object of my invention is to provide mechanism for moving the feed dog in a rectangular, positivelydeiined path, that is, the feed dog Vis raised and lowered in different but substantially vertical planes, and is fed and returned in different "but substantially horizontal planes. These positively defined motions cause the feed dog to engage the work efficiently and positively and to move in a horizontal plane for each stitch forming operation; and cause the feed dog to disengage the work and to move positively out of the way in preparation for the next stitch forming operation.

In the drawings:

Fig. 1 i-s an elevational View of a sewing nia-- chine embodying `my invention.

Fig. 2 is a bottom plan View of the mechanism located under .the bed plate of the machine.

Fig. 3 is a transverse, vertical, sectional view taken in the plane of the lines 3 3 on Figs. l and 2, looking in the direction indicated `by the arrows.

2 Fig. 4 is a .bottom plan view .of part .of the mechanism @under .the .bed plate, particularly `the eccentric strap rack, as viewed from the plane Y ofthe .line 4 4 on Fig. 3.

Fig. 5 is a vertical sectional view, .partly .in elevation, on an enlarged scale, showingY the eccentric and clutch mounted on the lower -end of the vertical drive shaft.

Fig. 6 is a transverse, vertical sectional viewcf part of the reversing mechanism, taken in the plane of the line 6-5 on Fig. 1.

Figs. '7 .and-8 are diagrammatic views showing the operati-ve connections between lthe feed shaft and feed dog and between the rise and fall shaft and feed dog, and the successive positions of the feed dogand its operativeconnectionsduring the rise. push, fall and pull 'motions of the feed dog.

Fig. 9 is an elevational view of apart of the reversing mechanism and its connection to the feed shaft.

Figs. 10 and 11 vare 'diagrammatic views showing vtwo vpositions of the slotted reversing `bracket and the roller movable therein, and illustrating the effect thereof von the feed shaft.

Conventional parts lof `the sewing machine shown `in Fig. 1 include the bed plate `2l), upright standard 421, overhanging arm 22, sewing head 23 and `presserfoot 24. The main driveshaft r25 extends horizontally .through the overhang-ing arm 22.4 It may be motor driven or treadle operated, as is well understood in the art.

Referring more particularly to that embodiment of my invention which I have chosen to illustrate in the drawings, the main drive shaft 25, through the gears 25, 21, drives the rotatable vertical shaft 28 located in the 4uprightstandard 2i I(Figs. '3 and 5) for actuating the rise and fall shaft E9 located beneath the bed plate of the machine. To the right of said shaft 23 is the vertical connecting rod 'Sil which is reciprocated by the eccentric T31 mounted on the horizontal shaft 2.5 `(Figs. 1 and '2) for actuating the feed shaft 3?..

The vertical shaft 28 has connected to its lower end a beveled -gear 33 which meshes with the beveledgear 34 fixed on the-end of the hook shaft 35 which is mounted in bearings 36 under the bed plate 2t. The hook shaft 35 has fixed on its free end the hook o-r loop taker, indicated as a whole at 3.1. The hook shaft 35 is rotated continuously in one direction by the rotatable shaft 28 so that the hook 31 will cooperate with the needle operating mechanism in the head in the stitch forming operation.

The vertical shaft 28 also actuates the rise and fall shaft 29. Said shaft 23 is connected to the shaft 29 through the following described mechanism: an integrally formed eccentric 38 and concentric clutch 39 are slidably mounted on the lower end of the shaft 23; the eccentric 38 and clutch 39 are spaced from each other by an annular recess 40; a pin 4| extends upwardly from the clutch through the recess 40 to a point opposite the low side of the eccentric 38 (Fig. 5). A pin 42 is fixed horizontally in the lower end of the shaft 28 and extends into an annular recess 43 between the shaft 28 and clutch 39. When the clutch is in a predetermined position, the pin 42 is adapted to enter a notch 44 formed internally in the clutch 39, as will be explained in the description of the operation of the machine,

An eccentric strap rack 45 is slotted at 46 and mounted on a headed bolt 41 which extends through the slot 46 into a 'fixed part of the machine beneath the bed plate 20 (Fig. 4). The strap rack 45 has a toothed rack 48 at its free end, and intermediate its ends is provided with a square opening 49 adapted to receive the eccentric 38 on shaft 28. The depending teeth of the rack 48 of the strap 45 engage the teeth 56 of the toothed segment which is fixed on the rise and fall shaft 29 bya set screw 52.

To insure keeping the rack teeth 48 in engagement with the teeth 50 of the segment 5|, I have provided a retaining lever 53 which is pivotally mounted on a pin 54 in a bracket 55 flxedly ccnnected to the under side of the bed plate 28. An adjusting screw, shown but not numbered, extends through the lever 53 near the pivotal mounting 54 and is engageable with the bed plate. The free end of the lever 53 has roller retaining fingers 56 for holding the roller 51 between them and in position for bearing on the rack 48 (Figs. 3 and 4).

The eccentric 38 and clutch 39, as a unit, are slidably mounted on the shaft 28 and are manually actuated by means of the plunger 58 provided with a control button 59 located above the bed plate 28, the plunger 58 being bent at right angles and connected at 68 to a clutch engaging fork indicated as a whole at 6|. The fork 6| is pivotally mounted by a bolt or screw 62 on a fixed part 63 of the bed plate of the machine. The free end of the fork is provided with spaced apart arms 64, 84, adapted to engage the clutch 39 as best shown in Figs. 2 and 3.

Referring now to the operative connections between the rise and fall shaft 29, the feed shaft 32, and the feed dog 65, reference to Figs. 2, 1 and 8 will show that the feed shaft 32 has xedly mounted on it a link 6B to which is pivotally connected the feed block rocker 61. The rise and fall shaft 29 has xedly mounted on it a link 68 pivotally connected at 69 to the link 19, and the latter is pivotally connected at 1| to the arm 12 of the feed block rocker 61. The rocker 61 is rigidly connected through the arm 13 to the feed dog 55.

The opposite end of the feed shaft 32 is operatively connected to the connecting rod 30 by the mechanism best shown in Figs. 2, 6 and 9, namely: the rocker arm 14, pivotally connected by the pin to the link 16 on which is rotatably mounted a roller 11 which is movable in the slot 18 of the reversing bracket 19. Said bracket 19 is pivotally secured to a xed part of the upright standard as indicated at 80 in Fig. 1. lAn arm 8| which extends rigidly frorn the bracket 19 is pivotally connected to the control lever 82 by means of which the position of the bracket 19 and its slot 18 is adjusted.

Bearing blocks 83, 84, bored to receive the shafts 29 and 32, are rigidly mounted on or cast with the bed plate 2 I.

Operation-The vertical shaft 28 rotates continuously when power has been applied to the .4 main drive shaft 25, and therefore continuously rotates the hook shaft 35, as heretofore explained. Said main drive shaft 25, through the eccentric 3| and connecting rod 38, continuously imparts 5 rocking motion to the feed shaft 32. The shaft 32, through its operative connections with the feed dog 65, thus constantly imparts reciprocating feed and return motions to the feed dog 65. For ordinary sewing7 these push and pull motions l0 take place in different horizontal planes through the reciprocating rocking motion of the rise and fall shaft 29, whereas for special Work such as mending, darning and the like, these push and pull motions are made to take place in a single 15 horizontal plane below the level of the bed plate,

by holding the feed dog in dropped position by means of the drop feed mechanism.

Said drop feed mechanism operates through the eccentric-clutch unit best shown in Figs. 3.

4 and 5. When the plunger 58 and fork 6| have been actuated to lift the eccentric 38 and clutch 39 to the position shown in said figures, the drive pin 82 will be out of engagement with the notch 44, and the vertical lock pin 4| will extend into the square slot 49 of the strap rack 45. The shaft 28 in its continuous rotation will carry the eccentric 38 and clutch 39 only to the position shown in Fig. 4, wherein the lock pin 4| prevents rotation of the eccentric 38. While the eccentric is idle, the strap rack 45 and toothed segment 5| remain stationary also, and the rise and fall shaft 29 becomes inoperative. In this position of the eccentric-clutch unit, the rise and fall shaft 29 and the connections between said shaft and the feed dog 85 hold said feed dog in its lowered or fall position, out of engagement with the work, and consequently the rocking movement of the feed shaft 32 results in reciprocating the feed dog 55 in one horizontal plane,

below the level of the bed plate, as indicated in Fig. 8.

When the plunger 58 and fork 6| have been actuated to lower the eccentric 38 and clutch 39 relatively to the shaft 28, the drive pin 42 will engage the notch 44 and drivingly connect the clutch unit 38-39 to the shaft 28, and the lock pin 4| will be lowered with the unit to a position where it cannot interfere with the rotation of the eccentric 38. Now the rotation of the shaft 28 results in rotation of the eccentric 38 and consequent reciprocation of the strap rack 45, which in turn rocks the segment 5| and the rise and fall shaft 29.

In this position of the eccentric 38, the rise fand fall shaft 29 and the connections between said shaft and the feed dog impart to said feed flog the alternating rise and fall movements, and consequently the rocking movement of the feed shaft 32 combined with the rise and fall move- 6o ments imparted by the shaft 29, result in reciprocatingr the feed dog 65 in two different horizontal planes, namely, in one direction in the raised, work-engaging plane, and in the opposite direction in the lowered, nonwork-engaging 65 plane.

Another element enters into the operation of the above described parts, namely, the control of the direction of movement of the feed dog when it is in the raised work-engaging position.

This is Acontrolled by the reversing mechanism (Figs. 1, 6, 9, 10 and ll), the adjusted position of which establishes the timing relationship between the operation of the rise and fall shaft 29 and the feed shaft 32, and determines whether the feed dog is to move away from or toward the operator when in itsraised or push stroke. The path .traveled by the feed'dogs in this embodiment of my` invention may'be likened to. a rectangnlarV path starting at 3 on the face of a clock, rising to l0, moving horizontally toy the right to 2, down to 4, and then horizontally to the left to: 8'. The. direction" of movement over this path' may be: clockwise or anti-clockwise.

As'shown in. Fig. '7., the movement of the` feed dog is in. the anti-clockwise direction, that is, from the. solid line tothe dotted line position, toward the.- operator, as. in reverse sewing. Using theillustration above stated, the movement is from 2. on` the face of a clock toward the left` to in Figure '7; thendown to 8 andl to the right across to 4:," as in Fig. 8.

Fig. 10v shows diagrammatically the position of the. reversing bracket l and the rocked position of the feed shaft 32. when the feed dog Se is intended to be mo-ved from right to left on its raised or push stroke, as in Fig. 7. Fig. 1l shows diagrammatically the position of the reversing bracket 'I9 and of therocked. feed shaft 32v when the feeddog is intended to be moved in the opposite direction.,- from left to right, on its raised or push stroke.

It will be understood that while the reversing mechanism functions` to control the direction of movement of the feed dog, which is essential. to the control ofi ordi-nary and reverse sewing, said reversing mechanism may bein either position without affecting the operation of the machine for drop feed work. Obviously when the feed dog 65 is held in dropped position'by means of the plunger 58, fork 69, clutch 39, eccentric 3B, strap rackt5, segment 5l and rise and fall shaft 2'9, the horizontal reciprocation of the feed dog imparted by the feed shaft 32 takes place in one single horizontal plane below the level of the bed plate, where the dog cannot engage the work, and therefore the operator is enabled to move the work manually as desired.

Changes may be made in details of construction and form of parts without departing from the scope of my invention as set forth in the appended claims.

I claim:

1. A sewing machine comprising a bed plate, a feed dog movably mounted therein, a horizontal power shaft rotatably mounted above the bed plate, a rotatable vertical shaft driven by the power shaft, a reciprocating connecting rod also driven by the power shaft, a rotatable horizontal hook shaft journaled under the bed plate and geared to said vertical shaft, a feed dog lifter rock shaft operatively connected to the feed dog for imparting rise and fall motions to the feed dog, a feed rock shaft operatively connected to the feed dog for imparting feed and return motions to the feed dog, said lifter and feed rock shafts being journaled under the bed plate parallel with the hook shaft, operative connections between the feed rock shaft and said reciprocating connecting rod for imparting continuous rocking motion to said feed shaft, and operative connections between said lifter rock shaft and said rotatable vertical shaft for imparting rocking motion to the lifter shaft including drop feed mechanism for rendering the lifter shaft inactive.

2. The sewing machine defined by claim 1, in which said drop feed mechanism comprises an eccentric-clutch unit slidably mounted on said rotatable vertical shaft, a toothed rack slidably mounted to engage the eccentric-clutch for actuation by the eccentric portion thereof, a toothed segment. iixedlymountedA on theV lifter rock Vshaftl and in mesh with the; rack, a manually actuated fork. engaging'` said clutchV member for slidably moving the eccentric-clutch onsaid rotatable vertical shaft; and means on the rotatable shaft and said eccentric-clutch for imparting rotation to' theLeccentric-clutch'.

3. A` sewing machine comprising a bed plate, a feed' dog movably mounted thereon, a rotatable vertical shaft, a feed dogv lifter rock shaft, a feed rock shaftrfor imparting feed and return motion tothe feed dog, means for imparting continuous rocking. motion to said feed shaft, and operative connectionsA between said rotatable vertical shaft and said lifter rockshaft for imparting rocking motion to the lifter shaft including drop feed mechanism for rendering the lifter shaftinactive, said drop feed mechanism comprising an eccentric-clutch unit slidably mounted on said rotatable vertical shaft, said unit having integrally formed cam and clutch members vertically spaced from each other, the clutch being concentric re1- atively to said' rotatable vertical shaft, a slidably mounted'toothed rack, a toothed segment iixedly mounted on the lifter rock shaft and in mesh withy the rack, a manually actuatedfork engaging said` clutch for slidably moving the eccentricclutch uniti onV said vertical' shaft, a pin extending' vertically from the clutch member for engaging the toothed rack when the unit is in raised' position on thel shaft, and a recess in the clutch` member for engaging a protruding part of the vertical. shaft when the eccentric-clutch u-nit is `in lowered position on the shaft, whereby said uni-t is4 caused to. rotate with the shaft.

4L A` sewing machine comprising a bed plate, a feed dog movablymounted thereon, a rotatable vertical. shaft, a feed dog lifter rock shaft, a feed rock shaft for imparting feed and return motion to the feed dog, means for imparting continuous rocking motion to said feed shaft, and operative connections between said rotatable vertical shaft and said lifter rock shaft for imparting rocking motion to the lifter shaft including drop feed mechanism for rendering the lifter shaft inactive, said drop feed mechanism comprising an eccentric-clutch unit slidably mounted on said rotatable vertical shaft, said unit having integrally formed cam and clutch members vertically spaced from each other, spaced apart ribs on the circumferential surface of the clutch member, the clutch being concentric relatively to said rotatable vertical shaft, a slidably mounted toothed rack, a toothed segment xedly mounted on the lifter rock shaft and in mesh with the rack, a manually actuated fork provided with arms adapted to engage the clutch between said ribs for slidably moving the eccentric-clutch unit on said vertical shaft, means on the clutch member engaging the toothed rack when the unit is in raised position on the shaft, and means on the rotatable shaft and said clutch member for operatively connecting them and imparting rotation to the eccentric-clutch unit when the unit is in lowered position on the shaft.

5. A sewing machine comprising a bed plate, a feed dog movably mounted thereon, a rotatable vertical shaft, a feed dog lifter rock shaft, a feed rock shaft for imparting feed and return motion to the feed dog, means for imparting continuous rocking motion to said feed shaft, and operative connections between said rotatable vertical shaft and said lifter rock shaft for imparting rocking motion to the lifter shaft including drop feed mechanism for rendering the lifter shaft inactive,

said drop feed mechanism comprising an eccentric-clutch unit slidably mounted on said rotatable vertical shaft, said unit having integrally formed cam and clutch members vertically spaced from each other, a toothed rack slidably mounted to engage the eccentric-clutch for actuation by the eccentric portion thereof, a toothed segment fixedly mounted on the lifter rock shaft and in mesh with the rack, a manually actuated fork engaging said clutch member for slidably moving the eccentric-clutch on said vertical shaft, means on the rotatable shaft and on said eccentric-clutch unit for imparting rotation to the said unit, and a lever pivotally and adjustably mounted on a fixed part of the bed plate, having its free end bearing on the toothed rack and holding it in mesh with the teeth of the segment fixed to the lifter rock shaft.

6. A sewing machine comprising a bed plate, a feed dog movably mounted therein, a feed dog lifter rock shaft journaled under the bed plate and operatively connected to the feed dog, means for imparting rocking motion to said lifter shaft, a feed rock shaft parallel with the lifter shaft also journaled under the bed plate and operatively connected to the feed dog, and means for imparting continuous rocking motion to said feed shaft, said means for imparting rocking motion to said lifter shaft including drop feed mechanism for rendering the lifter shaft inactive, comprising a rotatable vertical shaft, an eccentricclutch unit slidably mounted on said vertical shaft, a toothed rack slidably mounted under the bed plate and provided with an aperture between its toothed portion and slidable mounting for engaging the eccentric-clutch for actuation by the eccentric member thereof, a toothed segment Xedly mounted on the lifter rock shaft having its teeth in mesh with the teeth of the rack, a manually actuated fork engaging said eccentric-clutch for slidably moving it up and down on said vertical shaft, and cooperating means on the vertical shaft and said eccentricclutch unit for imparting rotation to the eccentrio-clutch.

7. The sewing machine dened by claim 6, in which said eccentric-clutch unit comprises integrally formed cam and clutch members vertically spaced from each other, the clutch member being concentric relatively to the aforementioned rotatable vertical shaft on which the unit is slidably mounted, a pin extending vertically from the clutch member for engaging the toothed rack when the eccentric-clutch unit is in raised position on the shaft, and a recess in the clutch member for engaging a protruding part of the vertical shaft when the eccentric-clutch unit is in lowered position on the shaft, whereby said unit is caused to rotate with the shaft.

8. The sewing machine defined by claim 6, which includes a lever pivotally and adjustably mounted on a xed part of the bed plate, having its free end bearing on the toothed rack and holding it in mesh with the teeth of the segment xed to the lifter rock shaft,

CLARENCE S. BEST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 463,294 Mills Nov. 17, 1891 368,925 Angell Aug. 30, 1887 401,182 Leilich Apr. 9, 1889 1,773,638 Stephenson n Aug. 19, 1930 

